The retirements of tennis legends Roger Federer, Rafael Nadal and Serena Williams have made event promotion more challenging, but organizers must seize the chance to spotlight emerging talent, says the United Cup's tournament director.

The highly anticipated $10 million mixed-team event, which kicks off the season on Friday, is poised to do just that, with tournament chief Stephen Farrow confident that the future of the sport is in capable hands.

"It's true to say that from a promotional standpoint, it's very easy if you've got Roger Federer or Rafael Nadal turning up," Farrow told Reuters after the draw for the 18-team tournament was held in Sydney.

"You're talking about people who are absolute superstars of the sports arena. With those guys moving on, it does make it a bit more difficult to promote and tell the story of the athletes playing the event."

"I always see that as a positive because it's on all of us in tennis to tell the story of this new talent."

"We've got a lot of them playing the United Cup. They're incredibly exciting and captivating to watch. I'm not worried about the future."

Grand Slam contenders Alexander Zverev, Taylor Fritz, Iga Swiatek, and Coco Gauff will all be in action for their countries at the Dec. 27-Jan. 5 tournament staged in Perth and Sydney as they prepare for the Australian Open, which starts Jan. 12.

Farrow also said the United Cup was still building its brand and boosting awareness among fans and players.

"Last year we saw a really big step forward when we moved to a new format with one women's singles, one men's singles, and one mixed doubles. It was incredibly competitive."

"Now we've established ourselves on the tennis calendar two weeks before the Australian Open. We've seen with the field this year that players want to play this event."

Spain takes on Kazakhstan, while China meets Brazil on the opening day in Perth.